Portion of a display screen showing an icon



FIG. 1 is a front view showing the new design; and,

FIG. 2 is a front view showing an alternative embodiment of the new design.

The broken line showing of various regions in FIG. 2 and the unshaded areas there within form no part of the claimed design. The broken line drawing of a portion of a display screen is for illustrative purposes only and forms no part of the claimed design. 

The ornamental design for a portion of a display screen showing an icon, as shown and described. 